not too long ago i had a local mechanic put in my new used suspension (bilstein/eibachs). lately i have been hearing knocking noises from the rear. the noise sounds like its coming from the shock towers more on the the pass rear esp when hitiing bumps.. any thoughts ???
thanks
vtach
1986 928

 

If it sounds more like a klicking noise, I would bet on the sway bar bolts. Make sure that they are tightened to spec.

 

I agree with Schocki. Retorque all your fasteners. Hopefully your mechanic put all those pesky washers back in properly when he reinstalled the big pins. You might look closely at both sides to see if they match. Sometimes a spring does not seat properly on its perch and you have to coax it in place. Your mechanic should do this diagnostic work for you I would think or ask someone else to check.
Good luck,
Dave McK.

 

thanks guys
took it to a p-mechanic thinks both rear shocks need to come out - something went wrong with prior installation... maybe i will tackle this one myself...should not be that difficult i hope !
v-tach

 

Next time, make sure your P-mechanic has a set of Porsche Work Shop Manuals and actually uses them.

As you found out the hard way, not all 928 repairs are straight forward.

borland
90' S4, Slate Metallic

 

it was a local mechanic who did the install. the p-mechanic thinks somehow it was done incorrectly. i looked at some instructions --the rear shocks r/r look pretty straight forward. for some reason im getting a knocking noise from the rear like a shock is loose. i wonder what could be wrong ? washers missing ? not enough RTV ? anybody else with suggestions ?
thanks
v-tach
1986.5

 

On the bottom end of the coil-over, the lower shock eye is angled: it must be correctly positioned, and is intuitive which way is correct ...... but it can be fitted on bassackwards . Also, there are two washers with conical faces on one side - these MUST face into the recesses in the hub carrier. That pretty much takes care of the big pin assembly, with a large flat washer under each end nut.
On top of the strut, the three securing nuts (13mm on M10?) are moderately torqued from inside the hatch. As far as strange noises, insufficient torque on the sway bar drop links can also cause a "graunching" noise.

 

Adding to what Garth said, .....the bowed upper control arm can be installed upside down causing an interference and safety hazard.

 

I have exactly the same symptoms with my bilsteins - my mechanic (Paul Anderson and probably the leading 928 man in the UK) took everything back out and reassembled after double checking and the noise is still there. We even replaced the damper on the side the knocking seems to be coming from (NSR) but it made no difference. I just wonder whether it's a knock on effect (excuse the pun) on stiffer damper rates on the bushes etc - although my car (95 GTS) had only done 36,000 at the time so bushes etc should all be in relatively good nick. The car handles beautifully and I have got used to it now and decided to live with it.
Anyone else had similar experiences with Bilsteins?

 

Drmark, I did my Bilstein/Eibach about 1 1/2 years ago on my MY85 and had he same results. Checked and re-checked everything. Nothing loose, incorrectly installed, etc. Same as you, live with it, chalk it up to a stiffer suspension, cars handles great, did a couple of DE's with it.

 

I noticed a knock from the right rear sometimes when I make a sharp turn after I installed the Ott drop links. I'm living with it.

 

My G/F says I have noise at the rear...no fix in site.

 

Probably poor quality gas.

 

Actually I have a very similar noise coming from the rear of my car since install of Bilsteins. However, I kinda remember the same noise with the stock Boge's. However, it seems louder since the Bilsteins were installed. And since Ketchmi did the install, I'd bet my bottom dollar there wasn't a problem with it.

It's a clunking noise from the rear suspension when backing out of my driveway over the 1 inch curbing, or driving over any small bump.

Maybe it's something inherent to Bilsteins?

I remember having this conversation with Dave a while back. Can't remember exactly what he said. I'll give him a call, and maybe he'll chime in.

 

my porsche mechanic thinks its abnormal and wants to dissasemble the rear suspension or at least the pass rear for now. he thinks it should not make that noice - happens only over bumps --very annoying -- i cant remember if i had the same noise with the boge. i am not happy with spending more money
thanks guys
v-tach